The evolution of economic and social environments has caused interpersonal communication to be more important. Constantly associating with and communicating with all kinds of personnel can enrich and develop people themselves. Traditional social means can no longer meet people's demands. Internet social network has attracted a great amount of attention and been used by an increasing number of people, as the Internet social network is not limited by space and time and can establish connections among colleagues, classmates, and friends more easily.
The birth of instant messaging (IM) software makes these advantages of the Internet social network more prominent. People can easily and conveniently contact anyone in his/her own friend circle through the software. When needing to find a target user, a person can directly contact him/her if the target user is already in that person's friend circle.
However, as people are restricted by working and living environments, people's social network also has certain restrictions. When a certain target user to be found is someone who can be reached in daily life, it is relatively easy to find the target user within or relatively close to our social circles. However, in daily life, there may be some situations as below. For example, some target users that a person wants to find are not within our normal social circles, and therefore it may be difficult to find the target users by existing instant messaging software. A person can ask friends in a friend circle of the instant messaging software that whether their social networks have the target users to be found. It would be good if a user to be found is a friend of our direct friend, and we can ask our direct friend to provide information of the user to us. However, what if the users to be found are not the friends of direct friends? Although the person can still ask friends of friends to continue asking around in their friend circles, even if the target users can be found at last, information of the target users has to be finally returned to the person who initially sends the request through many links such as our friends, even friends of the friends, and the like. It is thus clear that, in this process, it has to occupy lots of user resources and system resources, and once a certain user forgets to return the information or does not return the information on time during the process, the initial user cannot timely obtain the information of the target users, or even cannot obtain the information at all.
In summary, how to help a user find any user that he/she wants to find more easily and conveniently becomes an urgent technical problem to be solved by those skilled in the art.